Background: Indicated interventions for adolescents with elevated depressive symptoms may help decrease rates of depression. The current study reports on the efficacy of Interpersonal Psychotherapy-Adolescent Skills Training (IPT-AST), a group indicated preventive intervention. Methods: Forty-one adolescents with elevated depression symptoms were randomized to receive either IPT-AST or school counseling (SC) as delivered by guidance counselors and social workers. Adolescents in the two intervention conditions were compared on depression symptoms, overall functioning, and depression diagnoses post-intervention and at 3-month and 6-month follow-up. Results: Adolescents who received IPT-AST had significantly fewer depression symptoms and better overall functioning post-intervention and at follow-up. Adolescents in IPT-AST also reported fewer depression diagnoses than adolescents in usual care. Conclusions: These results provide preliminary evidence of the efficacy of IPT-AST as an intervention for adolescents with subthreshold depression. Future research is needed to confirm the efficacy of IPT-AST in a larger and more diverse sample and to determine its long-term impact on depression symptoms and depression diagnoses.